/**
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * <p>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p>
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.tencent.mm.util;

import java.io.DataInput;
import java.io.DataInputStream;
import java.io.IOException;
import java.io.InputStream;

/**
 * @author shwenzhang
 */
public class ExtDataInput extends DataInputDelegate {
  public ExtDataInput(InputStream in) {
    this((DataInput) new DataInputStream(in));
  }

  public ExtDataInput(DataInput delegate) {
    super(delegate);
  }

  public int[] readIntArray(int length) throws IOException {
    int[] array = new int[length];
    for (int i = 0; i < length; i++) {
      array[i] = readInt();
    }
    return array;
  }

  public void skipInt() throws IOException {
    skipBytes(4);
  }

  public void skipCheckInt(int expected) throws IOException {
    int got = readInt();
    if (got != expected) {
      throw new IOException(String.format("Expected: 0x%08x, got: 0x%08x", expected, got));
    }
  }

  public void skipCheckChunkTypeInt(int expected, int possible) throws IOException {
    int got = readInt();

    if (got == possible) {
      skipCheckChunkTypeInt(expected, -1);
    } else if (got != expected) {
      throw new IOException(String.format("Expected: 0x%08x, got: 0x%08x", expected, got));
    }
  }

  public void skipCheckShort(short expected) throws IOException {
    short got = readShort();
    if (got != expected) {
      throw new IOException(String.format("Expected: 0x%08x, got: 0x%08x", expected, got));
    }
  }

  public void skipCheckByte(byte expected) throws IOException {
    byte got = readByte();
    if (got != expected) {
      throw new IOException(String.format("Expected: 0x%08x, got: 0x%08x", expected, got));
    }
  }

  public String readNullEndedString(int length, boolean fixed) throws IOException {
    StringBuilder string = new StringBuilder(16);
    while (length-- != 0) {
      short ch = readShort();
      if (ch == 0) {
        break;
      }
      string.append((char) ch);
    }
    if (fixed) {
      skipBytes(length * 2);
    }

    return string.toString();
  }
}
